Raw Materials
-Set screws shall be made of steel conforming to the requirements specified below.
-For property class 45H, other materials may be used provided that the torque test requirements are met. |
Property
Class |
Material |
Heat
Treatment |
Chemical Composition % |
| C |
P
max. |
S
max. |
| max. |
min. |
| 14H |
Carbon Steel1)2) |
- |
0.50 |
- |
0.11 |
0.15 |
| 22H |
Carbon Steel3) |
Quenched and Tempered |
0.50 |
- |
0.05 |
0.05 |
| 33H |
Carbon Steel3) |
Quenched and Tempered |
0.50 |
- |
0.05 |
0.05 |
| 45H |
Carbon Steel3)4) |
Quenched and Tempered |
0.50 |
0.19 |
0.05 |
0.05 |
1)Free-cutting steel may be used, with lead content 0.35% max., phosphorus content 0.11% max., and sulphur content 0.34% max.
2)Case hardening is allowed in the case of square-head set screws.
3)Steel with lead content 0.35% max. may be used.
4)Shall contain one or more of alloying elements chromium, nickel, molybdenum, vanadium or boron. |
Mechanical Properties
| |
Property Class |
| 14H |
22H |
33H |
45H |
| Vickers Hardness HV |
min. |
140 |
220 |
330 |
450 |
| max. |
290 |
300 |
440 |
560 |
| Brinell Hardness HB, F=30 D2 |
min. |
133 |
209 |
314 |
428 |
| max. |
276 |
285 |
418 |
532 |
Rockwell
Hardness |
HRB |
min. |
75 |
95 |
- |
- |
| max. |
105 |
- |
- |
- |
| HRC |
min. |
- |
- |
33 |
45 |
| max. |
- |
30 |
44 |
53 |
| Minimum Height Of Non-decarburized thread zone, E |
- |
1/2H1 |
2/3H1 |
3/4H1 |
| Maximum depth of complete decarburization, G (mm) |
- |
0.015 |
0.015 |
** |
| Surface Hardness HV 0.3 (max) |
- |
320 |
450 |
580 |
| Pitch of the thread |
P
mm |
0.5 |
0.6 |
0.7 |
0.8 |
1 |
1.25 |
1.5 |
1.75 |
2 |
2.5 |
3 |
3.5 |
4 |
| H1 |
mm |
0.307 |
0.368 |
0.429 |
0.491 |
0.613 |
0.767 |
0.920 |
1.074 |
1.227 |
1.534 |
1.40 |
2.147 |
2.454 |
E
min
mm
|
Property
Class |
22H |
0.154 |
0.184 |
0.215 |
0.245 |
0.307 |
0.384 |
0.460 |
0.537 |
0.614 |
0.767 |
0.920 |
1.074 |
1.227 |
| 33H |
0.205 |
0.245 |
0.286 |
0.327 |
0.409 |
0.511 |
0.613 |
0.716 |
0.818 |
1.023 |
1.227 |
1.431 |
1.636 |
| 45H |
0.230 |
0.276 |
0.322 |
0.368 |
0.460 |
0.575 |
0.690 |
0.806 |
0.920 |
1.151 |
1.380 |
1.610 |
1.841 |
Torque Requirements
| Nominal Thread Diameter |
Minimum Length Of Screw For Test (mm) |
Test Torque
N x m |
| Flat Point |
Cup Point |
Cone Point |
Dog Point |
| 3 |
4 |
4 |
5 |
5 |
0.9 |
| 4 |
5 |
5 |
6 |
6 |
2.5 |
| 5 |
5 |
6 |
8 |
8 |
5 |
| 6 |
8 |
8 |
8 |
8 |
8.5 |
| 8 |
8 |
10 |
10 |
10 |
20 |
| 10 |
10 |
12 |
12 |
12 |
40 |
| 12 |
16 |
16 |
16 |
16 |
65 |
| 16 |
20 |
20 |
20 |
20 |
160 |
| 20 |
20 |
25 |
25 |
25 |
310 |
| 24 |
25 |
30 |
30 |
30 |
520 |
|
